Switch box circuit controller having three circuit controlling conditions



Aprll 26, 1966 R. J. PASTOREL 3,248,508

SWITCH BOX CIRCUIT CONTROLLER HAVING THREE CIRCUIT CONTROLLING CONDITIONS Filed Sept. 25, 1963 INVENTOR ROBERT J. PASTOREL United States Patent SWITCH BOX CIRCUHT CDNTROLLER HAVING THREE (IIREUET GNTRLLING (IONDITIUNS Robert J. Pastoral, Chicago, IEL, assignor to Appleton Eiectric Company, Qhicago, BL, a corporation of iilinois Filed fiept. 25, 1963, Ser. No. 311,451 1 Claim. (Ql. 200-153) This invention relates to a circuit controller for electrical circuits, and more particularly to a manually operable circuit controller for starting and stopping electrical devices. In particular, the invention relates to a circuit controller of the type employed to control relays causing the operation of electrical motors. The circuit controller has an external cover of the conventional kind with a pivoted operating lever thereon for rotation between designated stop and start positions.

Because this type of circuit controller is widely em ployed, improvements in the quality of operation and in the economy of manufacture are of significant commercial value. Accordingly, an object of the invention is to operate electrical contacts within the circuit controller by a few relatively low-cost operating elements that serve not only to operate the contacts, but also which serve to detent themselves in at least one of these positions.

Another object of the invention is the provision of a simple,'one-piece control lever suitably contoured to perform the dual functions of operating the electrical contacts and for serving as a portion of a detent mechanism to hold the operating lever in at least one of its predetermined positions.

For reasons of safety and for providing an excellent locating action, toggle-like mechanisms are usually pre ferred to assure that the switch remains in a predetermined position. Accordingly, a further object of the invention is the arrangement of the control lever and an electrical contact operating element so that they form a toggle-like arrangement when the switch is in the predetermined position.

A further object of the invention is the utilization of a spring in the contact assembly for the dual purposes of assuring good electrical contact enclosure and of providing the biasing force for a detenting mechanism.

Other and further objects of the present invention will be apparent from the following description and claim and are illustrated in the accompanying drawing, which by way of illustration, shows a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claim.

In the drawings:

FIG. 1 is a perspective view of the circuit controller according to the preferred embodiment of the invention;

FIG. 2 is a sectional view showing the control lever for operating a contact plunger assembly;

FIG. 3 is a diagrammatic view showing the control lever in its neutral position after having operated the start contacts; and

FIG. 4 is a sectional view showing the control lever position in one of its contact operating positions.

Referring now to the drawings, and more particularly to FIG. 1, thecircuit controller is shown having a cast base 11 with opposed bosses 13 at each of its opposed ends. A top cover 14 is secured to the top of the base 11 by screw-type fasteners 15. The bosses 13 have central bores 16 therein through which electrical conduits may be extended for connection to the electrical terminals within the interior of the box-like base 11.

For the purpose of controlling an electrical circuit, such as a circuit for controlling the stopping and starting of an electrical motor, the circuit controller 10 has a winged operating lever 20 secured to a pivot shaft 21. The winged operating lever 20 has a pair of opposed finger buttons 23 and 24 which are suitably contoured to be en gaged by the fingers of a person operating the circuit controller. Depression of either of the finger buttons 23 or 24 rotates the winged operating lever 20 and causes the operation of electrical contacts, to be later described, within the circuit controller 10 to the position corresponding to either the start or stop markings, not shown, the markings being embossed on the buttons 23 and 24, respectively.

Integrally formed on the winged operating lever 20 is an upstanding apertured locking tab 25, having a central aperture 26 for alignment with one of three apertures 27, FIG. 2, on a vertical extension 28 of the top cover 14. When the apertures 26 and 23 are aligned, it is possible to insert the hook of a padlock through the aligned apertures 26 and 27 and lock the circuit controller in one of the three desired positions, namely start, running/ neutral, or stop, proceeding in a counterclockwise order in FIG. 1, or counterclockwise as shown in FIG. 3.

The winged operating lever 20 is secured to the pivot shaft 21 by a pin 3% extending through aligned apertures in the hub 31 of the winged lever 29 and in the pivot shaft 21. The pivot shaft 21 rotates within a horizontal bore 35 of the top cover casting 14. The pivot shaft 21 is limited against movement in the axial direction by a split locking ring 37 on the interior portion of the shaft 21 and by a leather washer 38 situated between the hub 31 of the winged lever 20 and the adjacent wall 39 of the top cover 14.

For the purpose of operating the electrical contact the pivot shaft 21 has fixedly secured on its inner end a control lever 40 which is secured thereto by a fastener 44 threaded in a tapped hole therefor in the end of pivot shaft 21. The control lever 40 is configured approximately like a bell crank and has a forward camming surface 44, FIG. 3, for depressing a start contact plunger 45 when the bell crank lever 40 is rotated in the counterclockwise direction from the position shown in FIG. 3 to bring the front camming surface 44 into'camming engagement with a rounded cam follower 46 formed on the upper end of the plunger 45.

For the purpose of depressing a plunger 50 when the lever 20 is in a stop position, the control lever 40 has a camming surface 51 on the leg 52 of the control lever 40 for camming against the rounded cam follower 55 formed at the top of the stop plunger 50. That is to say, when the control lever 40 is rotated in the clockwise direction from the position shown in FIG. 3 to the position shown in FIG. 4, the camming surface 51 is operable to depress the plunger 50 to the position shown in FIG. 4 wherein only the cam follower portion 55 of the plunger 50 is visible.

In addition to having the camming surfaces 44 and 51 for the start plunger 45 and stop plunger 50, the control lever 40 has a notched seat 53 therein, which is complementally shaped to the dome-like portion of the cam follower 55 so that the cam follower 55 can neatly seat within the notch 53 when the control lever 40 is in the position shown in FIG. 4. The stop plunger 50 is urged by a coiled compression spring 60 to move upwardly from the position shown in FIG. 2 to a position where a the shoulders 61 on the plunger 50 engage the shoulders of contact assembly holder 63. Thus, with the shoulders 61 in engagement with the under surface shoulders of contact assembly holder 63, the plunger 50 is prevented from further upward movement under the urging of the spring 60.

However, when the plunger 50 is in the position shown in FIG. 4, the coiled spring 60 is exerting a biasing force on the plunger 50 and through the cam follower 55 and com lementary seat 58 on the control lever 40, a force preventing the accidental falling of the winged operating level 20 to the on position. That is, to rotate the control lever 40 clockwise from the position shown in FIG. 4 requires the overcoming of the force exerted by the spring 60 which resists movement of a humped portion 65 past the top of the rounded cam follower 55. The cam follower 55 and the complementary seat 58 function in the manner of the conventional detent mechanism to hold an element in a given position. Likewise, the plunger 55 and leg 52 of the control lever 40 are like two links in a toggle mechanism in that when the plunger 55 and leg 52 become aligned with the center of rotation 44, the control lever 40 is locked in a straight line relationship as in a toggle mechanism.

The contact assembly 63 is shown in detail in FIG. 2 as having a plunger 50 slideable within a channel 69A. The contact assembly 63 is formed from molded plastic elements which are of identical halves, one of which halves 69 being shown in FIG. 2. When the other contact assembly half is joined to the contact assembly half 69, a contact assembly 63 is formed in which the plunger 50 and spring 60 are enclosed. The spring 60 is seated on the metallic spring clip element 70, which holds together the two halves along the bottom portions thereof.

An electrical connection is made by completing an electrical path from an upper contact bar 74 across the contact assembly 63 by a floating contact bar 75 to a contact bar (not shown) similar to the contact bar 74 but embedded in the other half of the assembly 63; a further electrical connection is made by a lower floating contact bar 80 engaging a lower contact bar 82 embedded in the wall of the assembly half 69 and engaging a contact bar similar to the contact bar 82 embedded in the opposite contact half. The upper floating contact bar 75 and lower floating contact bar 80 are positioned within a hollow channel 76' in the plunger 50 and are movable with the plunger 50 to bridge either pair of the spaced contact bars. As shown in FIG. 2, the contact bar 75 is in engagement with an upper contact 74 and bridges across to the identical upper contact (not shown), that is, so long as the plunger is in its upper position. When the plunger 50 is forced down into the stop position, the upper floating contact bar 75 moves down and away from the upper stationary contact 74 and a similar contact embedded in the other contact half. Thus, when the plunger 50 is depressed, an electrical circuit is broken.

The floating contact bars 75 and 80 are limited to vertical movement in the channel 76, and are separated by a compression coil spring 77 which assures good electrical contact by the contact tips on the contact bars 75 and 80.

The plunger 45 associated with the start position is provided with a lower pair of stationary contact bars (not shown) such-as the contact bars 82. Since the spring 60 keeps the plunger 45 and lower floating contact bar 80 in an upper position, the start circuit is normally open. The contacts of the start contact assembly may be termed make contacts in the sense that the contacts will be closed only while the control lever 40 is rotated in an extreme counterclockwise position,

that is, turned further in the counterclockwise direction than the position shown in FIG. 3. Release of the starting pressure by the operator on the winged operating lever 20 permits the spring of the start contact assembly 63 to move the plunger 45 upwardly to rotate the control lever 40 in a clockwise direction to the position shown in FIG. 3 which may 'be termed a running position since the motor will have been started, and is now running under its own holding circuit. In the running position, neither of the plungers 45 nor 50 is depressed.

From the foregoing it is believed to be apparent that the present circuit controller has an operating control lever 40 that performs the functions of causing the starting and stopping of an electrical motor, and has the capability of also cooperating to hold the handle of the circuit controller 10 in a predetermined stop position.

It should also be apparent that by having the axis of the control lever 40 in a straight line relationship with the rectilinearly guided plunger 50, that a toggle-like mechanism is formed for holding the control lever 40 in the stop position.

Hence, while I have illustrated and described the preferred embodiment of my invention, it is to be understood that this is capable of variation and modification and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claim.

I claim:

In a circuit controller having three circuit controlling conditions,

frame means;

shaft means in said frame means and rotatable by manual pressure on said shaft means;

cam means secured to said shaft means, first contact assembly means disposed beneath said shaft means, said contact assembly means including a spring biased plunger and contacts controlled thereby; detent surface means on said cam means for detenting engagement with said spring biased plunger means, said detent surface means movable into a straight line toggle relationship with said shaft means and said spring biased plunger to move said contacts to said first circuit controlling condition; second contact assembly means spaced from said first contact assembly means and having a spring biased plunger means and contacts controlled thereby; a camming surface on said camming means operable -by manual pressure to depress said second-men tioned spring biased plunger means and move said contacts of said second contact assembly means to a second circuit controlling condition; and

said second spring biased plunger means operable on release of manual pressure to cam said camming means and to turn said shaft means and move said contacts of said second contact assembly means to a third circuit controlling condition.

References Cited by the Examiner UNITED STATES PATENTS KATHLEEN H. CLAFFY, Primary Examiner. ROBERT K. SCI-LAEFER, Examiner. 

